Looking at the episode again it reminded me on how Charlie and Sweet Dee used to be back in the first season. If you remember back when the show first came on air Dee used to be the voice of reason and had the most common sense... but a decade of fukkery has turned her to what she is now.
Same thing for Charlie, he has always been the member of the gang that never tried to fukk anyone over but over the years he has been ignored more and more. That Health Inspection episode showed how much work Charlie always put in but never gets credit for.
It seems like had both Charlie and Dee lived on their own the past 10 years they would have had a good decent life, but as they both admitted the peer pressure from the others causes their constant destruction which allowed them to temporary let their guards down and have sex.
This show is fukking deep brehs